M3-0.5 x 16mm 內六角螺絲 | 平頭 內六角驅動 | 全牙 | 合金鋼 12.9級 熱處理黑色氧化 (600個/包)

The hex socket drive on these screws fits my Allen key perfectly, no stripping even after tightening several into aluminum. For 16mm length in a precision jig, the threading was clean all the way through every one.

Finally, a pack of M3 screws that actually have consistent threads all the way down—every one I've used so far has seated perfectly in my jig without any binding. The black oxide finish seems durable too, no chipping during installation.

These M3 flat head screws are the exact 12.9 grade I needed for building a jig, and the black oxide finish looks clean. At 600 per pack, they're a solid value for precision work, and the hex socket drive engages perfectly without stripping.